Seagate introduces a new drive interface: Ethernet

It’s not time to say goodbye to the old storage network quite yet, but a new combination of cloud, networking, and storage technology might mark the beginning of the end for SANs—Seagate has introduced a new storage architecture that puts Ethernet directly on the disk drive.

Called the Kinetic Open Storage Platform, the new approach turns disks themselves into servers, delivering data over the network to applications using an open application interface. The Kinetic platform is a combination of an open programming interface and intelligence and a network interface installed in the storage device itself. It's targeted mostly at companies looking to adopt the same sort of architecture in their data centers that they use to connect to cloud storage providers such as Amazon.

While the architectural approach Seagate is taking is an evolution of work already done by cloud giants such as Google and Facebook, it turns cloud-style storage into a commodity. And that could change how companies small and large think of networked storage—especially as they move toward using newer software development approaches to build their applications or move applications built on Amazon or other cloud services back within their firewalls.

The components of the Kinetic storage device.

Seagate

Kinetic uses the same sort of key-value pair approach pioneered by Google's distributed file system. The storage devices expose data as objects that abstract the physical blocks that data is stored in, without the overhead of a file system's directory structure. Applications don't need to go through an operating system's storage drivers to manipulate data—they simply send "get," "put," and "delete" requests to the storage system.

While this eliminates doing things like appending files, it allows for storage systems to be easily scaled up with the addition of more disks—there's no need to recreate a directory structure or remap storage blocks. It also eliminates the overhead associated with traditional storage area networks (SANs), where operating system calls for disk reads and writes can consume much of the bandwidth of the network.

Cutting out the middle man

Enlarge/ The Kinetic storage platform uses a collection of APIs to handle data access and management rather than a traditional network and operating system stack.

Seagate

Amazon uses the same sort of interface for its Simple Storage Service (S3), as do "big data" systems such as Hadoop and NoSQL databases such as Basho's Riak and MongoDB. But those other key-value, pair-based systems generally run atop operating systems and rely on servers to manage data.

Kinetic eliminates the server entirely, with all of the management being handled by the storage devices. Each Kinetic drive or SSD has its own key-value management logic, and the drives can communicate with each other to handle replication or movement of data. Seagate is publishing the application library developers will use to control these storage systems as open source.

Others have seen the benefit of moving intelligence further down toward the storage device itself for cloud applications. Facebook has been developing a similar storage model for its data centers using a "micro-server" in its Open Vault storage nodes.

Seagate's Kinetic is the first commercial product to take this step. But it probably won't be the last. While traditional SANs aren't exactly on the endangered species list, the continued shift toward cloud-based development for both large-scale and smaller applications is going to make Kinetic increasingly attractive to both big data center operators and smaller organizations looking to create their own internal cloud storage without tethering themselves to Amazon or Microsoft.

Ethernet's ubiquity and broad support is a major point in its favor; but I have to wonder (aside, of course, from whether Seagate is on the very short list of 'entities you should trust to write code that touches a network'...) is whether it's a good choice for a situation that is likely to be very high density, mostly short-range, and sensitive to power and cooling costs.

Is the plan that these 'kinetic' drives will be using an interface that 'looks' like ethernet, for the purposes of borrowing all the cheap and common hardware and software support; but runs over some sort of physical layer more suited to a storage layout that is going to be largely made up of very short runs, with the extra power and cost of longer runs mostly between racks, or is each drive going to have a little RJ45 jack?\

I'd certainly like to tell some of the more upmarket RAID-slingers where the can shove their prices; but, given that densities in the 45 drives/4U range are doable with basic commodity parts, I don't doubt that switch vendors would be happy to charge you for whatever you saved on RAID hardware unless something cleverer than just throwing a 48 port 1u at every drive enclosure is in the works...

Ethernet's ubiquity and broad support is a major point in its favor; but I have to wonder (aside, of course, from whether Seagate is on the very short list of 'entities you should trust to write code that touches a network'...) is whether it's a good choice for a situation that is likely to be very high density, mostly short-range, and sensitive to power and cooling costs.

Yeah, I'd have to wonder whether a high density storage host filled with SATA/SAS ports is more economical than additional switching capacity. Time for an ethernet-over-SAS protocol?

The only good thing here is the possibility to take this interface protocol which is pretty reasonable, just ignore the hardware which makes no sense, and make decent high density storage servers with the kinetic interface.

That's probably a software question: As best I can tell from Seagate's presentation, most of the savings are achieved by baking a minimal key/value store mechanism into the drive and then letting the application, (rather than expensive RAID controllers or OS-provided filesystem mechanisms), do the work of turning the drives into a useful resource, handle duplication between drives of things that cannot be allowed to be lost, etc.

For 'cloud' applications, that's a fairly normal requirement: the economics of 1/2 socket x86s or VMs costing next to nothing; but fancy-high-availability-all-in-one-box systems costing a moderate size fortune already demand that anybody playing at scale be working along those lines (or a financial institution with an IBM support contract worth more than some nation states).

For home use, though, I can't think of any (currently existing) software that would be comfortable without a filesystem (and partial exceptions, like MTP vs USB MSC for MP3 players, or DLNA media servers vs. keep-it-simple-stupid just a bunch of DVD rips on an SMB share, are mostly compelling arguments for Never Going There, and clinging to the traditional filesystem with both hands)...

Huh. I can't tell if I like this or not.My first reaction to reading that replication sounds like it is managed "peer to peer" was "ugh, wrong."

That being said, it depends on how much control you can exert over the workings. For example, can we implement a consistent-hash storage algorithm right on top of these, or do we have to disable the replication support before connecting them up?

I'm cautiously optimistic; this seems like it takes us a little closer to the kind of disk that the original ZFS design mentioned; one that you can access directly, freely taking "traditional" disk firmware duties away from it, and into user-space.

I also am not sure if I understand this properly. It would help to have another graphic showing the 'standard way of doing this' then I could compare just which elements have been stripped out.

So far, it seems like the ethernet-attached drives just declare themselves as part of a 'pool' of storage, and if that pool runs low, you just plug in more drives. Apps throw data at this pool, and the drives decide between themselves where to store it, and how many copies to make, and where to store the other copies. When an app wants data back, the pool finds it and throws it back.

One can dream anyway. Now I'm curious enough to actually go look at the link to Seagate's website, and behold, it actually answers some of these questions.

Seems like the drives do actually do a lot of inter-drive communication:

Quote:

Drives communicate in keys and values. For example, they do gets, puts and deletes. They allow applications to distribute objects and manage clusters while letting the drive efficiently manage functionality, such as

Overall, am quite impressed. Some small orgs that I've worked in could do with something like this, if the front end was no-brainer enough and the ethernet drives were reasonably cheap. Upfront costs would be cheap and the system would scale, and IT officers wouldn't have to beg the boss to fork out upfront for a suitably sized RAID with SSD caching (or deal with the nightmare of growing a RAID set that you haven't touched for a year or two, that can't be backed up because well, it's full and you can't afford an entire second RAID set to back it up to.)

The only good thing here is the possibility to take this interface protocol which is pretty reasonable, just ignore the hardware which makes no sense, and make decent high density storage servers with the kinetic interface.

I'd imagine something along the lines of what you see with modern blade-server chassis, where the blades all plug into the blackbox backplane, and then the management interface can map logical interfaces on the blade systems to some combination of whatever physical ports are available on the chassis or installed option cards and chattering among one another across the backplane.<br><br>

(Of course, if that ends up being the case, you may find yourself kissing the savings goodbye and handing them over to the chassis vendor, which wouldn't necessarily be an improvement, even if there are savings over conventional SATA/SAS drives for somebody to take...)<br><br>

That seems like it'll be the kicker: it seems very likely indeed that HDDs that are direct evolutionary descendants of pre-networking microcomputer boot disks are not the best design for 'cloud scale' applications. However, architecturally-superior solutions have a nasty habit of foundering on a combination of user inertia and vendor greed: users need to see a good chunk of the savings if dealing with application-level modification is to be even remotely sensible; but the vendor selling the architecturally-superior system always wants to take advantage of the fact that it hasn't been commodified to hell and back, and pocket the savings themselves, or start adding totally proprietary option cards, and management software license fees, and so on.<br><br>

Does Seagate have OEMs lined up (or is it willing to do the job itself?) to do the ugly-but-necessary job of building boring, low-margin, HDD cages to support hundreds ('drawer' style 3.5-inch HDD cages, with the x86 server included, are usually 45-48 drives/4u, so ~800 drives if you totally cram a 72u, maybe more like 700 if you leave some room for switching and cable management at the top of the rack, don't know about 2.5 inch or smaller; but maybe 3x the number of drives, in rough numbers?) So, anywhere between 700 and 2400 GbE interfaces per 72u? Somebody had better be prepared to make thin margins on a custom design, or that'll cost a damned fortune...<br><br>

Similarly, how excited, exactly, will Seagate be if another HDD manufacturer (or a conventional storage server vendor, as a software abstraction layer for their product) implements a system complaint with Seagate's API? Will they throw a fit? Announce their confidence in victory through superiority? Play passive-aggressive versioning games in an attempt to break competitor's workalikes?

This is interesting and has lots of potential, although there are quite a few things unclear. From what I see on Seagate's site, authentication appears to be only by server and, authorization is by application role. Seagate doesn't elaborate beyond that. IMO, they need to provide more than a few bullet points to address security if they want people to take this seriously. At least give us a use case because I can easily see cases where such simplistic approach to security would not meet common corporate requirements, if I understand it correctly. And I hope to see this product reviewed by Ars

Overkill maybe for a home server. They mention that this system is designed for capacity rather than performance. How much terabytes a home server would ever need?

I'm pushing 12tb for my home setup. I'm a fairly light consumer of media, but have home generated photos & video. Oh, and I'm about to father my first child. I'm expecting that to blow my setup out of the water.

This is interesting and has lots of potential, although there are quite a few things unclear. From what I see on Seagate's site, authentication appears to be only by server and, authorization is by application role. Seagate doesn't elaborate beyond that. IMO, they need to provide more than a few bullet points to address security if they want people to take this seriously. At least give us a use case because I can easily see cases where such simplistic approach to security would not meet common corporate requirements, if I understand it correctly. And I hope to see this product reviewed by Ars

Just hurry up and bring out an optical ssd/hdd interface. Only problem is good optical switches aren't cheap

The optical interface is called fibre channel. Because optical switching isn't cheap they decided to do FC over copper to the drives. Then they realized how stupid that was and went with SAS (over copper). (To be fair IIRC FC over copper precedes SAS.)

Just hurry up and bring out an optical ssd/hdd interface. Only problem is good optical switches aren't cheap

The optical interface is called fibre channel. Because optical switching isn't cheap they decided to do FC over copper to the drives. Then they realized how stupid that was and went with SAS (over copper). (To be fair IIRC FC over copper precedes SAS.)

It didn't matter what the bus was as the hard drives weren't physically fast enough to grow with the FC spec anyways, no point having a 3200 MB/s pipe when the drive is only 600 MB/s.. waste of money..

Don't forget the switch, at another $700 per port. (Minimum eight ports, currently.)

10G Ethernet has stubbornly defied the price curves of Moore's Law and just about every other technology advance. Granted, it's a hairy problem to solve while still using copper infrastructure, but damn, another year goes by and it's still not feasible on the desktop.

Interesting. Does it handle failover? Replication? I wonder what random access performance is like using SSDs.

From the sounds of things the actual hardware is simply a normal external HDD, there's no mention of anything like a server rack in the article.

There could be some sort of logic in the cloud layer that allows those sort of activities, but if it exists working with it will be interesting, it's the first time anything like this has been done, Seagate will make mistakes with the management tools. And those are going to be the systems biggest weak point, to do the sort of things you want will require working with them, and while it SHOULD be easy to set up a group of drives using them for the first time, but any expansion will not go smoothly

It's also not going to be friendly to physically set up, each drive will need its own power supply and Ethernet port/cable and Ethernet has a minimum length on cable

Overkill maybe for a home server. They mention that this system is designed for capacity rather than performance. How much terabytes a home server would ever need?

I'm pushing 12tb for my home setup. I'm a fairly light consumer of media, but have home generated photos & video. Oh, and I'm about to father my first child. I'm expecting that to blow my setup out of the water.

Most cloud object storage solutions (S3, swift, ceph) aren't known for speed or latency. On the contrary, they eschew both for scalability. They want to handle 100,000 gets per second, they don't care as much about whether each get takes 100ms and transfers at 2mbit/s. I can think of many good use cases for such a thing locally, but SAN replacement isn't one of them.

Reading through the piece on Seagate's site, I don't think this is meant to be a replacement for SAN, but more the traditional file server (Internal RAID on a server). I could see this as be an advantage for SMB that don't invest a lot in their infrastructure and just need some cheap file serving storage that is local.They are using the same "You already have Ethernet in the Datacenter" argument that is used to sell iSCSI (Feel free to argue that point for a while). What little info here doesn't really seem to point to any uses cases above SMB though - Ethernet, especially GbE (they don't seem to mention 10GbE on the site) wouldn't be used for much above CIFS / NFS in a small environment. Couple that with the unknown latency introduced by the APIs, and no direct block level access to the disk, I don't see this replacing iSCSI (let alone FC) any time soon.The custom APIs are going to be a killer for anything other than file serving for this - until MS & VMware evaluate it for inclusion in their Hypervisors. Interesting piece - thanks for posting this.

Overkill maybe for a home server. They mention that this system is designed for capacity rather than performance. How much terabytes a home server would ever need?

I'm pushing 12tb for my home setup. I'm a fairly light consumer of media, but have home generated photos & video. Oh, and I'm about to father my first child. I'm expecting that to blow my setup out of the water.

I was thinking more about >100TB

Sorry for answering the question not the intention.

Lets just say that I do blow my box out of the water, that 12TB gets trebled in the next year due to family functions, parental excitement & prepping multiple suitable entertainment for my child. I don't think that is extravagant & I don't have a decade of DVDs to rip. I've also stopped deleting the majority of my data over the past 5 years, and am intending for backups to be much older than my current 2 years if only for nostalgic use in a few years time.

Who know how many more children my wife & I end up deciding to have. We are also quite concerned about welfare children & have been leaning towards also adopting or fostering. Maybe in the next 5 years the children will be old enough to be generating their own data (I hope). In two or 3 years I can see us starting to push the 100TB you dismiss as unnecessary for a home user. Is there any industry where data storage requirements is decreasing?

Now, I don't really think I'm going to be hooking up 100TB by this, but just because a business could easily use >100TB and this method is suitable, doesn't mean there isn't a reasonable use under 100TB.

Overkill maybe for a home server. They mention that this system is designed for capacity rather than performance. How much terabytes a home server would ever need?

I'm pushing 12tb for my home setup. I'm a fairly light consumer of media, but have home generated photos & video. Oh, and I'm about to father my first child. I'm expecting that to blow my setup out of the water.

I was thinking more about >100TB

Sorry for answering the question not the intention.

Lets just say that I do blow my box out of the water, that 12TB gets trebled in the next year due to family functions, parental excitement & prepping multiple suitable entertainment for my child. I don't think that is extravagant & I don't have a decade of DVDs to rip. I've also stopped deleting the majority of my data over the past 5 years, and am intending for backups to be much older than my current 2 years if only for nostalgic use in a few years time.

Who know how many more children my wife & I end up deciding to have. We are also quite concerned about welfare children & have been leaning towards also adopting or fostering. Maybe in the next 5 years the children will be old enough to be generating their own data (I hope). In two or 3 years I can see us starting to push the 100TB you dismiss as unnecessary for a home user. Is there any industry where data storage requirements is decreasing?

Now, I don't really think I'm going to be hooking up 100TB by this, but just because a business could easily use >100TB and this method is suitable, doesn't mean there isn't a reasonable use under 100TB.

Ethernet's ubiquity and broad support is a major point in its favor; but I have to wonder (aside, of course, from whether Seagate is on the very short list of 'entities you should trust to write code that touches a network'...) is whether it's a good choice for a situation that is likely to be very high density, mostly short-range, and sensitive to power and cooling costs.

Is the plan that these 'kinetic' drives will be using an interface that 'looks' like ethernet, for the purposes of borrowing all the cheap and common hardware and software support; but runs over some sort of physical layer more suited to a storage layout that is going to be largely made up of very short runs, with the extra power and cost of longer runs mostly between racks, or is each drive going to have a little RJ45 jack?\

Many form factors are possible. But the current implementation is 60 drives with 2 10G ethernet connections. Applications can talk to drives directly over TCPIP using their API without having to worry about which chassis they are in. End users can assemble the chassis with the bandwidth and network infrastructure appropriate for their use case.

They seem to be following the Facebook idea of deconstructing the traditional server - splitting out the hardware components into a mass block that can do one task really well. Actually, I wouldn't be surprised if Facebook bought into this tech - massive network-attached storage of key-value data pairs seems to be exactly what they'd need.

In two or 3 years I can see us starting to push the 100TB you dismiss as unnecessary for a home user.

Ah, the old semantic difference between a home user and a typical home user...

100TB is currently at least 25 drivers and 4000$ without enclosures. I think its fair to say that it's still quite some time away for an average home user.

In my experience, most home users have just zero to one external drives. A RAID with four devices already is somewhat rare even among prosumers (and well catered for). So I don't really see a market for a more scalable system among home users, either.

Sean Gallagher / Sean is Ars Technica's IT Editor. A former Navy officer, systems administrator, and network systems integrator with 20 years of IT journalism experience, he lives and works in Baltimore, Maryland.